Window Fan

ABSTRACT

In the specification and drawings a window fan is described and shown. The window fan cools a room using outside air when the room air meets certain criteria relative to a set point and the outside air meets certain preselected criteria relative to the indoor air. The window fan may also exhaust room air to the outside when the room air meets certain criteria relative to a set point and the outside air meets certain preselected criteria relative to the indoor air

CROSS REFERENCES TO RELATED APPLICATIONS

None.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

None.

REFERENCE TO SEQUENTIAL LISTING, ETC.

None.

BACKGROUND

1. Field of the Invention

This invention relates to a seasonally installed window fan. Morespecifically, the invention relates to a seasonally installed window fanwhich cools a room using outside air when the room air meets certaincriteria relative to a set point and the outside air meets certainpreselected criteria relative to the indoor air.

2. Description of the Related Art

Prior art window fans are utilized to move stagnant air, cool internalbuilding areas or rooms when air conditioning is not available. Thereare various known problems however, with prior art fan structures.First, as depicted in FIG. 15, prior art fans in many cases only pullair into a room and fail to exhaust air which causes poor circulationwithin the room and therefore hinders cooling. Alternatively, other fansystems pull air into a room and exhaust air in the same vertical planeor elevation. Therefore these fan systems fail to eliminate temperaturestratification and reduce cooling effectiveness.

Another problem related to prior art fans is that fan units do noinhibit water passing through a housing and into a room when the fan isoperated while a rain event is occurring. Consequently, during rainevents, many window fans may not be operated without drawing water intothe building.

Another problem with prior art window units is the limited control offan operation. Most prior art units are manually operated, meaning auser must turn the fan on and off as desired. It would be desirable touse a window fan when specific outside air criteria are met, so that theair conditioning system in the building or home is not needed when theoutside air is cool and of a saturation or humidity level which would becomfortable to an occupant of the building or room.

Additionally, the use of the dew point and humidity controls would allowfor increased comfort and energy savings by limiting the use of airconditioning in the building or home. Such limited use of naturalresources is desirable.

It would be desirable to create a window fan unit which overcomes theseand other deficiencies in order to decrease energy consumption, moreefficiently cool interior areas of a building, commercial, residentialor other, and improve occupant comfort while ultimately saving money oncooling by using outside air where applicable.

SUMMARY

In some embodiments a window fan cools a building interior and comprisesa housing having an exterior side for positioning exteriorly of thebuilding and an interior side for positioning interiorly of thebuilding. The housing has an outside air intake though which outside airis entrained on the exterior of the building; the outside air intakebeing positioned lower on a surface of the housing. The housing has anoutside air output in fluid communication with the outside air intake;the outside air output positioned in the building interior. The outsideair intake and the outside air exhaust are in fluid communication with afirst fan. The outside air intake has an outside louver and the outsidelouver has a preselected geometry which inhibits rain from entering theduct. A first motor is connected to the first fan causing rotation andentraining of the outside air from the building exterior into the airintake. An inside air exhaust is on an exterior surface of the housingpositioned above the outside air intake, the inside air exhaust forcingcontaminants in the outside air away from the outside air intake. A damis disposed interiorly of the air intake and inhibits contaminants frompassing through the duct in the housing. A second exhaust fan rotates todraw air from the building interior and forces air outward near a baseof the housing. A second motor is connected to the second exhaust fancausing rotation and entraining of the inside air from within thebuilding to outside the building. The outside air output and the insideair intake may be on the housing for positioning in the buildinginterior. The window fan may further comprise actuable louvers on theoutside air output and the inside air intake. The window fan may furthercomprise a control panel for operating the window fan. The control panelmay include an electronic controller which signals opening and closingof the actuable louvers. The window fan may have a first airflow pathand a second airflow path. The first airflow path may be separated fromthe second airflow path by a partition. One of the first airflow pathand the second airflow path may draw air into the building interior. Thepartition may have a sloped surface for draining any water from thehousing. The window fan may further comprise a well positioned adjacentthe dam for collecting water and draining the water from the housing.

In some embodiments a window fan system comprises a housing having aframe and a partition defining a first air flow path and a secondairflow path through the housing. One of the first and second flow pathdraws outside air into a building and the other of the first and secondflow path draws inside air out of the building creating a circulationpath. A first blower is in fluid communication with the first airflowpath and a second blower is in fluid communication with the secondairflow path, the first and second blowers creating airflows. A dam isdisposed along one of the first and second airflow path. The daminhibits water from passing from through the housing with the outsideair and has a sloped surface causing the water to gravity drain to awell. The well has drain apertures releasing the water from the hosinginterior to the exterior. A rear louver disposed over the inside airexhaust and outside air intake has a plurality of fins of preselectedgeometry which inhibit passage of water through the louver. The insideair exhaust blows water and contaminants away from the outside airintake.

In some embodiments a window fan comprises a housing having an airintake and an air exhaust output both in the housing and on an exteriorside of a building. The window fan also comprises an air output on aninterior side of the building, the air output being in fluidcommunication with the air intake through a duct in the housing. The airexhaust is in fluid communication with an exhaust intake on a buildinginterior side of the housing. A first fan is disposed vertically above asecond fan within the housing. One of the first fan and the second fanis in flow communication with the air intake and the air output, theother of the first fan and the second fan is in flow communication withthe air exhaust and the exhaust intake. The first fan and the second fanmay draw warmer air from the interior side of the building and coolerair from the exterior side of the building. The first fan and the secondfan may remove warm air from in the building and increase circulationfor improved cooling. The window fan may further comprise a partitionseparating a first airflow path from a second airflow path. The windowfan may further comprise a first partition separating a first airflowpath from a second airflow path. The window fan may further comprise thefirst airflow path and the second airflow path moving in oppositedirections through the housing. The window fan may further comprise amovable louver system for positioning on a building interior side of thehousing. The window fan may further comprise at least one actuatingmotor connected to a linkage for opening and closing louvers.

In some embodiments a window fan system comprises a housing having acontrol panel. The window fan system also comprises a first airflow pathhaving a first blower drawing outside air into the system and exhaustingthe outside air into the system and exhausting the outside air inside abuilding. The window fan system also comprises a second airflow pathhaving a second blower drawing inside air into the system and exhaustingthe inside air outside the building. The window fan system alsocomprises a room air intake in flow communication with the secondairflow path and an outside air exhaust in flow communication with thefirst airflow path, the room air intake disposed above the outside airexhaust. The window fan system may further comprise a dam positionedgenerally along the second airflow path and inhibiting water fromreaching the second blower. The window fan system may further comprise awell disposed at a lower edge of the dam. The window fan system mayfurther comprise a louver system which closes the first and secondairflow paths. The window fan system may further comprise a motor whichactuates a linkage. The linkage may actuate a plurality of louvers inthe first airflow path. The linkage may also actuate a plurality oflouvers in the second airflow path.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this invention,and the manner of attaining them, will become more apparent and theinvention will be better understood by reference to the followingdescription of embodiments of the invention taken in conjunction withthe accompanying drawings, wherein:

FIG. 1 is a perspective view of a window fan system positioned in awindow sill for use;

FIG. 2 is a side schematic view of a room circulation pattern showingboth intake into and exhaust from the room;

FIG. 3 is a rear perspective view of the window fan system with thehousing structure removed;

FIG. 4 is a perspective view of the housing of the window fan systemwith much of the internal structure removed;

FIG. 5 is a partially sectioned perspective view of the window fansystem;

FIG. 6 is a side section view of the window fan system;

FIG. 7 is a partially sectioned lower perspective view of the window fansystem;

FIG. 8 is a front perspective view of the window fan unit with thehousing structure removed;

FIG. 9 is a rear perspective of the room air exhaust and room air intakeincluding linkage removed from the window fan system;

FIG. 10 is a second rear perspective view of the structure shown in FIG.9;

FIG. 11 is a perspective view of the linkage and louvers for the roomair intake with the louvers in a first position;

FIG. 12 is a perspective view of the linkage and louvers for the roomair intake in a second position;

FIG. 13 is a perspective view of the linkage and louvers for the outsideair exhaust with the louvers in a first position;

FIG. 14 is a perspective view of the linkage and louvers for the outsideair exhaust with the louvers in a second position;

FIG. 15 is a side schematic of a prior art window fan having limited airmovement;

FIG. 16 is a top view of an embodiment of a control panel for use withthe window fan system;

FIG. 17 is a schematic representation of an embodiment of a controlsystem for a window fan system;

FIG. 18 is a flow diagram of an embodiment of the generalized logic of acontrol when a fan button of the window fan system is actuated by auser;

FIG. 19 is a flow diagram of an embodiment of the generalized logic of acontrol when a set point adjustment button of the window fan system isactuated by a user; and

FIG. 20 is a flow diagram of an embodiment of the generalized logic of acontrol when automatically operating the window fan system.

DETAILED DESCRIPTION

It is to be understood that the invention is not limited in itsapplication to the details of construction and the arrangement ofcomponents set forth in the following description or illustrated in thedrawings. The invention is capable of other embodiments and of beingpracticed or of being carried out in various ways. Also, it is to beunderstood that the phraseology and terminology used herein is for thepurpose of description and should not be regarded as limiting. The useof “including,” “comprising,” or “having” and variations thereof hereinis meant to encompass the items listed thereafter and equivalentsthereof as well as additional items. Unless limited otherwise, the terms“connected,” “coupled,” and “mounted,” and variations thereof herein areused broadly and encompass direct and indirect connections, couplings,and mountings. In addition, the terms “connected” and “coupled” andvariations thereof are not restricted to physical or mechanicalconnections or couplings.

Furthermore, and as described in subsequent paragraphs, the specificmechanical configurations illustrated in the drawings are intended toexemplify embodiments of the invention and that other alternativemechanical configurations are possible.

Referring now to the drawings wherein like numerals indicate likeelements throughout the several views that are shown in FIGS. 1-20various aspects of a window fan system. The window fan system inhibitsrain passage through the housing and dispels the rain without the watercontent entering the interior area of the building. The window fan unitalso comprises a damper or louver system to open and close vents tolimit heat transfer through the system when the fans are turned off.Additionally, the fan unit has a ducting arrangement which pulls airinto a room and exhausts air from the room to improve circulation andutilizes a fan arrangement to aid with the circulation. The fan systemalso utilizes a control system to utilize outside air having desirablecharacteristics which cools the room and may be also used with existingair conditioning, therefore decreasing the reliance on an airconditioning system, and saving energy and costs associated with airconditioning operation.

Referring now to FIG. 1, a perspective view of a window fan system 10 isdepicted on a window sill and with a window sash (both shown in brokenline) engaging an upper surface of the window fan system 10. Positionedabout the lower portion of the fan system 10 is a lower housing 12 whichwraps around the front and sides of the fan system 10 and may be formedof metal, plastic or other resilient material and which hasaesthetically pleasing qualities. A power cord 14 is shown extendingfrom a side of the lower housing 12 and may extend to a power supplysuch as an in-wall power outlet (not shown). Adjacent to power cord 14is a sill bracket 16 which allows for adjustable connection to thewindow sill wherein the window fan system 10 is positioned. Although asash type window is depicted, it should be understood that use of thewindow fan system 10 may be used with slider type window which slides ina horizontal direction rather than a vertical direction.

Within the lower housing 12 is an outside air exhaust 18. When outsideair is entrained into the fan system 10 and passes through at least onefan within the window fan system 10, the outside air is exhausted intothe building or room through the outside air exhaust 18. The outside airexhaust 18 is positioned on the lower area of the housing so that anupper intake 30 can remove hotter air from the room. The outside airexhaust 18 may be opened or closed to allow or inhibit airflow into theroom or area being cooled.

Above the lower housing 12 is an upper housing 20 which may also beformed of metal, plastic or other resilient material like the lowerhousing 12 and may be matching. The upper and lower housings 20, 12 ofthe exemplary embodiment are depicted as separate housing pieces,however, such housing elements 12, 20 may be combined into a singleone-piece housing. Additionally, the upper housing 20 comprises acontrol panel 22 having a display 24 and at least one control button 26.Adjacent to the control panel 22 is a room exhaust intake 30. The windowfan system 10 also exhausts air from inside the building to outside inorder to improve circulation within the room or building. Thus, coolerair comes into the building through the outside air exhaust 18 andhotter air is withdrawn from the room through the upper room exhaustintake 30. With the room exhaust intake 30 on the upper surface of thewindow fan system 10, the room exhaust intake 30 can better draw warmair from the room and move it outside. Conversely, the outside airexhaust 18 is at a lower position, as this air is cooler than the warmerair being exhausted by the room exhaust intake 30. This configurationaids circulation since warm air rises and cooler air descends.

The surrounding window structure is shown in broken line to provideenvironmental understanding of how the window fan system 10 is placed inthe window and when the sash is closed against the upper surface of theupper housing 20. Positioned on the upper housing 20 is an adjustablesash bracket 28. This bracket provides an adjustable width to fitvarious sizes of window sash. The bracket 28 also provides adjustabilityto compensate for the position the window fan 10 is inwardly oroutwardly relative to the window sill beneath the system 10. Forexample, some windows will require further positioning of the system 10toward the interior of the building than other windows. The sash bracket28 also aids to compensate for such adjustments.

Referring now to FIG. 2, a side schematic view of a room is depicted. Awindow fan system 10 is depicted in a sidewall of the room. A lower fandraws air into the room which circulates across the room, up an oppositewall, along the ceiling and down the wall in which the window fan unit10 is positioned. Additionally, it will be understood that the airmoving into the room may move along the walls toward the window fansystem 10. As the air moves along the walls toward the system 10, anyrising temperature of the air will cause the air to rise nearer the fansystem 10. A second upper fan draws air from within the room and out toatmosphere. As previously indicated, the upper fan is utilized to drawair from the room since warmer air will be higher in the room. Incomparison with FIG. 15, one of skill in the art will recognize thatwhere the prior art device fails by not removing air from the interior,the instant embodiment removes warmer air increasing circulation, whichultimately aids in cooling the room. The vertical circulation patterncreated by the fan system 10 eliminates temperature stratification ofprior art devices with air intake and air exhaust both in the samevertical elevation

Referring now to FIG. 3, a rear perspective view of the window fansystem 10 is depicted. The rear side of the window fan system 10 ispositioned on the outside of the building being cooled both drawing airinto the room and exhausting air out of the room. With the upper housing20, the lower housing 12 and the rear louver 32 all removed, a frame 40is revealed. The frame 40 comprises a first side member 41 and a secondopposed side member 43. Both the first side member 41 and the secondside member 43 are vertical members and substantially parallel to oneanother in the exemplary embodiment although such design should not beconsidered limiting. Along the upper side of the frame 40 and connectingthe first side member and second side member 41,43 is an upper framemember 42. The upper frame member 42 is substantially horizontal andopposite to an opening 44 which is defined by a first strut 45 and anopposed second strut 46. Around the mid-portion of the frame 40, in avertical direction is a partition 38 which separates the upper exhaustportion 50 from the lower intake portion 52 of the window fan system 10.On the upper side of the fan partition 38, is an upper fan housing 54.Beneath the partition 38 in the lower intake portion 52 is a lower fanhousing 56. Each of the housings 54, 56 may be formed of one or morehousing portions which are connected in various manners or alternativelymay be formed integrally.

Referring now to FIG. 4, a perspective view of a window fan system 10 isdepicted with the internal components of the system 10 removed. Throughthe openings of the upper housing 20, the rear louver 32 may be seenwhich is positioned on the outwardly facing side of the window fansystem 10. The rear louver 32 covers the upper exhaust portion 50 andthe lower intake portion 52 (FIG. 3). These portions 50,52 are separatedby the partition 38 (FIG. 2) so as to create two separate air pathways.The lower intake portion 52 pulls outside air into the system 10 directsthe air into the building or home through the outside air exhaust 18.The upper exhaust portion 50 pulls air from the room or buildinginterior through the room exhaust intake 30 and directs this warmer airout of the upper half of the rear louver 32.

Within the lower area of the system 10, a dam 60 may be seen adjacentthe rear louver 32. The dam 60 is located generally between the firstand second struts 45, 46 (FIG. 2). The dam 60 may be separately formedand positioned between the struts 45,46 or, alternatively the dam 60 maybe integrally formed with lower housing portion 12, frame 40, or otherportions of the fan system 10. In either formation, the dam 60 inhibitswater passage through the fan system 10. Water passing through the lowerportion of rear louver 32 encounters the dam 60 as it moves into ortoward the lower intake portion 52. The dam inhibits the water dropletfrom passing though the housing and into the room. The dam 60 performsthis function by creating a reservoir for water droplets which fall outof the airstream being pulled into the housing. In other words, the dam60 effectuates removal from the entrained water droplets from theairflow. Afterward, the fallen water droplets are gravity fed to a well62 (FIG. 6) where the water may drain through the housing and out of thesystem 10 and may be aided by the lower fan at the bottom of the fanblade.

Referring now to FIGS. 5 and 6, a partially sectioned rear perspectiveview and side sectioned view of the window fan unit 10 are depicted. Therear louver 32 comprises a plurality of vertical fins 32 a and aplurality of horizontally extending fins 32 b. The horizontallyextending fins 32 b are tilted at an angle which slopes downward fromthe inside of the system 10 to the outside. The fins 32 a, 32 b arefixed and are sloped in order to deflect rain which might otherwise bepulled into the lower half of the louver 32 and into the lower intakeportion 52. According to the exemplary embodiment, the slope of thehorizontal fins is 5%, although such slope should not be consideredlimiting as other slopes may be utilized. Additionally, an aspect ratioof the rear louver 32 is defined as being about two-to-one (2:1). Theterm aspect ratio means that, as measured between vertical fins 32 a,the width of the horizontal fin 32 b is twice the vertical distancebetween louvers. Again this aspect ratio is merely exemplary, as otherratios may be utilized. The illustrative aspect ratio is utilized alsofor its ability to deflect rain which may be entrained near the lowerintake portion 52 of the louver 32.

From this view, one skilled in the art will realize that the upperexhaust portion 50 (FIG. 2) which blows air outwardly through the upperportion of the louver 32 also aids to clear the airspace immediatelyabove the lower intake portion 52 (FIG. 2) of louver 32 of rain andother contaminants which may be otherwise pulled into the lower intakeportion 52 by the lower fan. For purpose of this description, the termcontaminants should be understood to mean rain, snow or other weatherelements in addition to other elements which may be found in the outsideair. Thus, the present embodiment utilizes a louver 32 having fincharacteristics which aid to inhibit rain from entering the window fansystem 10. The arrangement of an upper fan system 80 blowing outwardlyand a lower fan 74 pulling air inwardly aids to blow rain away from thelower portion of louver 32 inhibiting rainwater from entering the windowfan system 10 during use. Additionally, any rainwater which passesthrough the rear louver 32 may be impinged on the dam 60 adjacent thelower intake fan 74 or alternatively slowed by the dam 60 causing thewater to fall or drain into the well 62.

As shown near the bottom of the window fan system 10, and between thefirst and second struts 45,46, the dam 60 has an upper surface 61 whichgenerally slopes from an upper point closer to fan 74 to a lower pointnear the louver 32. The dam 60 receives some water which passes throughthe louver 32. Typically, the flow path of the water may be interruptedby the louvers 32 and this disruption in velocity causes the waterdroplets to fall onto the upper surface onto the dam 60. The slope ofdam 60, in combination with gravity, causes water to drain down this damslope into a well 62 (FIG. 6).

Moving away from the louver 32, beyond the dam 60, an intake fanassembly 70 is depicted. The fan assembly 70 includes a motor 72 whichmay be a 120 Volt motor having a high speed of approximately 1425 RPM, amedium speed of approximately 1322 RPM, and a low speed of approximately1184 RPM. Connected to the fan motor 72 is a blower or fan 74. Theblower or fan 74 may be a centripetal fan which draws air into the topportion beneath the partition 38. Alternatively, various types of fansmay be used, for example centrifugal, tangential or cross-flow fans. Theblower 74 is generally cylindrical in shape having a plurality ofhorizontal fins which may be slightly curved and connected by aplurality of axially aligned ribs. The blower 74 is operably connectedto the fan motor 72 and spins about a central axis with the motor 72. Inthe views shown in FIGS. 5 and 6, the motor 72 rotates in asubstantially counterclockwise direction which pulls air inwardlythrough the lower portion of louver 32 and moves the air upwardlythrough the blower housing 56 and expels the accelerated air through theroom air exhaust 18. The blower housing 56 is connected to the partition38 which separates the lower intake portion 52 (FIG. 2) from the upperexhaust portion 50 (FIG. 2).

Still referring to FIGS. 5, 6 and 7, the partition 38 includes a slopedportion closest to the rear louver 32. The sloped portion of thepartition 38 also utilizes gravity to remove any water which may gatherin this area of the fan and drains this water to the dam 60 or the well62. At the downhill side of the dam 60 is a well 62. The function of thewell 62 is to receive water which runs off the slope surface of the dam60 and remove the water from the fan system 10. A plurality of apertures64 are seen at a lower surface of the window fan unit 10. Theseapertures 64 function as drain holes and are located generally in thebottom of the well 62. A plurality of ribs 66 are positioned on thelower surface of the dam 60 which eliminates the need to make a soliddam 60 and saves weight while strengthening the part. As previouslydescribed the dam 60 may be separately formed or integrally formed withthe housing 12, frame 40, or other parts.

Above the partition 38, an upper exhaust fan assembly 80 is positioned.Similar to the lower fan assembly 70, the upper exhaust fan assembly 80comprises a fan motor 82 and a centripetal fan or blower 84. The upperfan assembly 80 removes air from the building interior through the roomexhaust intake 30, through the blower 74 and out to atmosphere throughthe upper portion of the rear louver 32.

Referring now to FIG. 8, the window fan unit 10 is depicted with thelower housing 12 and upper housing 20 removed. Extending from the frame40 is a room exhaust intake 30 having a plurality of louvers 34 whichare pivotally positioned within a louver frame 36. The louver frame 36functions as a duct through which air passes from the room, through theroom exhaust intake 30, louvers 34 and into the upper fan assembly 80.Beneath the louver frame 36 is the upper fan cowling 56 which is curvedto proximate the curvature of the blower 84 and includes a plurality ofstiffening ribs along the outer surface thereof.

Beneath the room exhaust intake 30, is the outside air exhaust 18, whichalso comprises a louver housing 90 and a plurality of pivotable louvers92. The louver housing 90 also functions as a duct adjacent to the lowerfan assembly 70 and allows air passage through the outside air exhaust18 into the room or building where the window fan unit 10 is positioned.

Referring now to FIG. 9, a perspective view of the room exhaust intake30 and the outside air exhaust 18 is shown in a rear perspective viewthrough which air passes from a building interior to the outside of thebuilding. The upper louver frame 36 includes a plurality of louvers 34positioned therein. The louvers 34 may be pivoted open to allow air flowwhen the system 10 is in operation. Alternatively, when the windowsystem 10 is not operating, the louvers 34 may be closed to inhibit flowof air from the interior of the room to the outside or vice versadepending on the temperature difference between the outside ambient airand the inside air temperature. The louver frame 36 includes a pluralityof moldings and fastening apertures for connection to the frame 40 (FIG.7) or other components of the system 10.

Beneath the room exhaust intake 30 is the outside air exhaust 18. Thelouver housing 90 defines a duct area through which air passes from thefan system 80 to the room interior. Within the lower housing 90 are aplurality of pivotally connected louvers 92 which also open and closedepending on the state of the window fan system 10. The lower housing 90also includes a plurality of moldings and apertures for connecting thelower housing 90 to the frame 40 or adjacent structure. As best seen inFIG. 8, positioned about the front area of the housings 36, 90 andlouvers 34, 92 are trim elements which define portions of the outerhousings 12, 20.

The louvers 34,92 may, according to one embodiment, move independentlyof one another. Alternatively, in the exemplary embodiment depicted, anddescribed hereinafter, a linkage system 100 is utilized to open andclose the louvers 34,92 simultaneously. The linkage system 100 comprisesan actuated motor 102. An actuator arm 104 is operably connected to themotor with a pivot point 106 and first and second linkage connections108,109.

Referring now to FIG. 10, a perspective view of the linkage system 100is depicted. Connected to the arm 104 at pivot point 109 (FIG. 9) is alower linkage 110. The lower linkage 110 connects to a lower louverpivot mechanism 112. This mechanism 112 includes at least one arm 114,connected to lower linkage 110. The upper linkage 120 extends to anupper pivot mechanism 122 having an arm 124. Both arms 114,124 pivot tomove the corresponding louvers 92,34.

Referring now to FIGS. 11 and 12, perspective views of the pivotmechanism 122 are depicted with the louvers 34 in first and secondpositions. Arm 124 is generally v-shaped and pivotally connected to thelouver frame 36. A slide member 126 is connected to the arm 124 andslides along a surface of the louver frame 136 as the arm 124 rotateswith movement of linkage arm 120. Each of the louvers 34 are operablyconnected to the slide 126 so that movement of the arm 124 causesmovement of the slide 126, and therefore movement of the louvers 34. Insum, according to the exemplary embodiment, the actuator motor 102pivots each of the louvers 34 with a single motion via the arm 124 andslide member 126. As shown in FIG. 11, the louvers 34 are in an openposition. As the arm 124 is rotated and the slide member 126 moves, thelouvers 34 rotate to a closed position.

Referring now to FIGS. 13 and 14, perspective views of the lower pivotmechanism 112 are depicted with the louvers in first and secondpositions. Depending from the actuator motor 102 is the lower linkage110 which engages an arm 134. Extending from the lower housing 90 is apivot structure about which the arm 134 rotates. Also connected to thearm 134 is a lower slide member 136. The plurality of louvers 92 areeach pivotally connected to the slide member 136 so that rotation of thearm 134 causes pivotal movement, opening or closing, of the louvers 92.

Referring now to FIG. 16, a top view of a second embodiment of a controlpanel 122 is depicted. Both control panels 22, 122 may be in electroniccommunication with the fan systems 70, 80 as well as linkage system 100for controlling the window fan system 10. Control panel 122 may belocated, for example, in a similar location as control panel 22 onwindow fan system 10. Control panel 122 includes a display 124 thatprovides an area for displaying a current dry bulb temperature of theroom or interior air and an area for displaying the current set pointtemperature that has been selected by a user. A power push button 126 ais provided to enable a user to selectively power window fan system 10and a fan push button 126 b is provided to enable a user to cause lowerfan 74 and upper fan 84 to be set to a low, medium, high, or automaticsetting. AUTO LED 125 a, HIGH LED 125 b, MED LED 125 c, and LOW LED 125d are selectively illuminated to convey to a user which setting isselected for lower fan 74 and upper fan 84. Similarly, ON LED 125 e isilluminated when the window fan system 10 is powered on to convey to auser that it is powered. A set point “+” button 126 c and a set point“−” button 126 d are provided to enable a user to increment the setpoint upwardly or downwardly, respectively. The area of display 124 fordisplaying the current set point temperature conveys to a user thecurrently selected set point.

Referring now to FIG. 17, a schematic representation of an embodiment ofa control system for a window fan is depicted. Power button 126 a, fanbutton 126 b, set point “+” button 126 c, and set point “−” button 126 dof control panel 122 are in selective electrical communication withcontroller 210, causing one or more signals to be sent to controller 210when they are actuated. Controller 210 is also in electricalcommunication with AUTO LED 125 a, HIGH LED 125 b, MED LED 125 c, LOWLED 125 d, and ON LED 125 e of control panel 122 and is programmed toselectively illuminate the LEDs based on input received from a user viapower button 126 a, fan button 126 b, set point “+” button 126 c, and/orset point “−” button 126 d. Outdoor sensor 96 and indoor sensor 98 arealso in electrical communication with controller 210 and may communicateone or more signals to controller 210 that are indicative of one or morecharacteristics of exterior air and interior air, respectively. Suchcharacteristics include, without limitation, dry bulb temperature, wetbulb temperature, absolute humidity, specific humidity, relativehumidity, pressure, and/or dew point temperature. Controller 210 is alsoin electrical communication with relays 214 for lower fan motor 72 andupper fan motor 82 and drivers 218 for actuated motor 102. The relays214 are in electrical communication with lower fan motor 72 and upperfan motor 82 and can be selectively activated to cause lower fan motor72 and upper fan motor 82 to be driven at a desired speed of a pluralityof speeds. In some embodiments three relays are provided and may beselectively activated to drive lower fan motor 72 and upper fan motor 82at either a low, medium, or high speed. The drivers 218 are inelectrical communication with actuated motor 102 and may be selectivelyactivated to accurately control actuated motor 102 and, resultantly,louvers 34 and 92. In some embodiments four driver channels may beprovided in electrical communication with actuated motor 102 and may beselectively activated to provide full stepping or half stepping of theactuated motor 102.

In some embodiments Power button 126 a, fan button 126 b, set point “+”button 126 c and set point “−” button 126 d may be membrane type buttonsthat engage a corresponding switch on a circuit board adjacent thecontrol panel 122 when actuated. The circuit board may also include thecontroller 210, AUTO LED 125 a, HIGH LED 125 b, MED LED 125 c, LOW LED125 d, ON LED 125 e, display 124, relays 214 for lower fan motor 72 andupper fan motor 82, and/or drivers 218 for the actuated motor 102. Thecontrol may be a PIC microcontroller model number PIC18LF4331-1/PT, theactuator motor 102 may be a PM Step Motor 24BYJ model manufactured byBest Electronics Industrials Co., Ltd., and outdoor sensor 96 and indoorsensor 98 may be Relative Humidity and Temperature Modules HTG3500Series manufactured by Measurement Specialties. Referring briefly toFIGS. 5-7, outdoor sensor 96 may be located just inside louver 32 nearthe base of louver 32 and strut 45. The outdoor sensor 96 is locatednear lower intake portion 52 so as to be appropriately exposed toexterior air. Referring briefly to FIG. 8 where a portion of controlpanel 22 is shown cut away, and to FIGS. 5 and 6, indoor sensor 98 maybe located on a circuit board 205 adjacent the control panel 22 in aposition so as to be exposed to the interior air and be relativelyunaffected by any heat generated by other components attached to thecircuit board 205. In FIGS. 1 and 5 apertures 23 are shown that extendthrough control panel 22 to enable indoor sensor 98 to be appropriatelyexposed to indoor air. Outdoor sensor 96 and indoor sensor 98 may belocated elsewhere on window fan system 10 or may be located remote fromwindow fan system 10, so long as they are located to be responsive toone or more characteristics of the exterior air and interior air,respectively. Outdoor sensor 96 and indoor sensor 98 may be in wired orwireless electronic communication with electronic controller 210.

Referring now to FIG. 18, a flow diagram shows an embodiment of thegeneralized logic of controller 210 when fan button 126 b is actuated bya user. If it is the first time fan button 126 b has been pressed, thecontroller 210 causes AUTO LED 125 a to be illuminated and controller210 automatically operates the window fan system 10. An embodiment ofthe automatic operation of the window fan system is shown in detail inFIG. 20 and described in detail hereinafter. If it is the second timefan button 126 b has been pressed, the controller 210 causes HIGH LED125 b to be illuminated, communicates with relays 214 to cause them toall be activated, causing lower fan motor 72 and upper fan motor 82 tooperate at a high speed. Controller 210 also communicates with drivers218 to ensure actuated motor 102 is appropriately stepped to placelouvers 34 and 92 in an open position to allow airflow through windowfan system 10. If it is the third time fan button 126 b has beenpressed, the controller 210 causes MED LED 125 c to be illuminated,communicates with relays 214 to cause two relays to be activated,causing lower fan motor 72 and upper fan motor 82 to operate at a mediumspeed. Controller 210 also communicates with drivers 218 to ensureactuated motor 102 is appropriately stepped to place louvers 34 and 92in an open position to allow airflow through window fan system 10. If itis the fourth time fan button 126 b has been pressed, the controller 210causes LOW LED 125 d to be illuminated, communicates with relays 214 tocause a single relay to be activated, causing lower fan motor 72 andupper fan motor 82 to operate at a low speed. Controller 210 alsocommunicates with drivers 218 to ensure actuator motor 102 isappropriately stepped to place louvers 34 and 92 in an open position toallow airflow through window fan system 10.

Referring now to FIG. 19, a flow diagram shows an embodiment of thegeneralized logic of controller 210 when set point “+” button 126 c isactuated by a user and when set point “−” button 126 d is actuated by auser. If the set point “+” button 126 c is actuated controller 210increments the currently stored set point up by one degree. Thecontroller 210 also causes the area of display 124 that displays thecurrent set point temperature to be updated to reflect the current setpoint temperature selected. If the set point “−” button 126 d isactuated controller 210 increments the currently stored set point downby one degree. The controller 210 also causes the area of display 124that displays the current set point temperature to be updated to reflectthe current set point temperature selected. In alternative embodimentsincrements smaller or larger than one degree may be used.

Referring now to FIG. 20, a flow diagram shows an embodiment of thegeneralized logic of controller 210 automatically operating the windowfan system 10. In the flow diagram of FIG. 20 interior dry bulbtemperature (I. D. B.), exterior dry bulb temperature (E. D. B.),interior dew point (I. D. P), and exterior dew point (E.D.P.) areanalyzed by controller 210. In some embodiments indoor sensor 98 andoutdoor sensor 96 supply signals to controller 210 that are indicativeof measured interior and exterior dry bulb temperatures and relativehumidity levels and controller 210 calculates an interior and exteriordew point that correspond to the measured interior and exterior dry bulbtemperatures and relative humidity levels. In some embodimentscontroller 210 could calculate dew points by referencing a table, suchas a table containing dry bulb temperatures, relative humidity levels,and dew point temperatures to determine a dew point temperature thatcorresponds to the measured dry bulb temperature and relative humiditylevel. In some embodiments controller 210 could calculate dew points byusing one or more formulas. For example, the dew point could becalculated using the formula: Dew Point Temperature=[(17.271*Dry BulbTemperature)/(237.7+Dry Bulb Temperature)]+ln(Relative Humidity/100),where the temperatures are in degrees Celsius and “ln” refers to thenatural logarithm.

In other embodiments indoor sensor 98 and outdoor sensor 96 couldmeasure alternative or additional characteristics of the interior andexterior air and supply signals to controller 210 indicative of suchcharacteristics. Such characteristics include, without limitation, drybulb temperature, wet bulb temperature, absolute humidity, specifichumidity, relative humidity, pressure, and/or dew point temperature.Controller 210 could then use these alternative or additionalcharacteristics to compare, either directly or indirectly, exterior andinterior dry bulb temperatures and exterior and interior dew points foruse in the automatic operation of the window fan system 10. For example,instead of measuring interior and exterior relative humidity,determining the interior and exterior dew point from the relativehumidity measurements, and directly comparing the interior and exteriordew point, interior and exterior relative humidity could be measured,interior and exterior specific relative humidity determined from therelative humidity measurements, and interior and exterior specificrelative humidity directly compared. Comparison of the exterior specifichumidity and interior specific humidity may indirectly indicate theexterior dew point is less than the interior dew point. For example, ifthe exterior specific humidity is less than the interior specifichumidity it may indirectly indicate that the exterior dew point is lessthan the interior dew point. Other characteristics of exterior and/orinterior air may be measured and analyzed to directly or indirectlydetermine if the exterior dew point is less than an interior dew point.Temperatures can be set, measured, calculated, and/or displayed inCelsius and/or Fahrenheit as desired.

If automatic operation of the window fan system 10 has been chosen by auser, at step 252 controller 210 determines if the interior dry bulbtemperature as indicated by indoor sensor 98 is greater than the currentset point temperature plus one degree. Comparing the interior dry bulbtemperature to the current set point temperature plus one degree at thispoint in the flow diagram prevents excessive cycling of the lower fanmotor 72 and upper fan motor 82. If at step 252 the interior dry bulbtemperature is determined to be greater than the current set pointtemperature plus one degree, at step 254 controller 210 determines ifthe interior dry bulb temperature is greater than the current set point.If the interior dry bulb temperature is greater than the current setpoint, at step 256 controller 210 determines if the exterior dry bulbtemperature is less than the interior dry bulb temperature. If theexterior dry bulb temperature is less than the interior dry bulbtemperature, at step 258 controller 210 determines if the exterior dewpoint minus five tenths is less than the interior dew point. If so, atstep 260 then the controller 210 turns the motor flag on and openslouvers 34 and 92.

The controller 210 then determines at step 262 if the difference betweenthe interior dry bulb temperature and the current set point temperature(Δ D.B.) is less than or equal to two. If so, at step 266 the controller210 activates the necessary relays to drive the lower fan motor 72 andupper fan motor 82 at low speed. If the difference between the interiordry bulb temperature and the current set point temperature is not lessthan or equal to two, the controller 210 determines at step 264 if thedifference between the interior dry bulb temperature and the current setpoint temperature is greater than two and less than or equal to three.If so, at step 268 the controller 210 activates the necessary relays todrive the lower fan motor 72 and upper fan motor 82 at medium speed. Ifthe difference between the interior dry bulb temperature and the currentset point temperature is not greater than two and less than or equal tothree, then at step 270 the controller 210 activates the necessaryrelays to drive the lower fan motor 72 and upper fan motor 82 at highspeed.

Once the controller 210 has activated the necessary controls to drivethe lower fan motor 72 and upper fan motor 82 at low speed in step 266,medium speed in step 268, or high speed in step 270, a two minutecountdown timer is started in step 274. After the two minute timer iscompleted the controller 210 checks to see if the motor flag is on instep 276 (the motor flag will be on if the conditions of steps 254, 256,and 258 were met in the previous loop). If the motor flag is on thencontroller 210 will proceed to determine if the conditions of steps 254,256, and 258 continue to be met. If the conditions of steps 254, 256,and 258 are met, controller 210 will again check the difference betweenthe interior dry bulb temperature and the current set point temperatureat steps 262 and 264 to determine if the speed at which the lower fanmotor 72 and upper fan motor 82 are being driven needs to be adjusted.If the conditions of steps 254, 256, or 258 are not met than at step 272the motor flag will be turned off if it is on, lower fan motor 72 andupper fan motor 82 will also be turned off, and then the two minutetimer of step 274 executed. Following execution of the two minute timer,the process will proceed to step 252 (since the motor flag is no longeron) to determine if the indoor dry bulb temperature is greater than thecurrent set point temperature plus one degree. If the interior dry bulbtemperature is not greater than the current set point temperature plusone degree, controller 210 again executes a two minute timer at step 274and after the timer has run again proceeds to step 252 to determine ifthe indoor dry bulb temperature is greater than the current set pointplus one degree.

Automatic operation of the window fan system 10 will continue until auser chooses a different fan setting through actuation of fan button 126b or powers the window fan system down through actuation of power button126 a. Automatic operation of the window fan system 10 brings exteriorair into an interior area and exhausts interior air to an exterior areawhen doing so would be advantageous in cooling the interior area asdesired by a user. Automatic operation of the window fan system 10 mayresult in energy savings without requiring consistent monitoring by auser and without the need to sync the window fan system 10 with an airconditioner or other device.

The methods and control systems described herein, as well as variationsthereof, may be implemented in an air conditioning unit that includes acompressor and one or more fans that draw exterior air into an interiorarea. Such an air conditioning unit may also include one or more fansthat exhaust interior air to an exterior area. The compressor of the airconditioning unit may be selectively deactivated when bringing exteriorair into an interior area and/or exhausting interior air to an exteriorarea would be advantageous in cooling the interior area. For example, ahotel room air conditioning unit or a window room air conditioner unitmay be installed in a wall or window and extend between a room and theoutside. The air conditioning unit may include an interior sensor thatmonitors one or more characteristics of the air in the hotel room and anoutside sensor that monitors one or more characteristics of the outsideair. The air conditioning unit may include a fan that draws air from theoutside and into the hotel room. Such a fan may be the same as, ordistinct from, a primary air conditioning fan that blows air into thehotel room that has first been cooled through an evaporator or otherdevice. The air conditioning unit may be programmed to utilize thecompressor to cool air being blown from the air conditioning unit into aroom interior when the desired set point is less than the current roominterior temperature and bringing exterior air into the room interiorwould not be advantageous in cooling the interior area. The hotel roomair conditioning unit may further be programmed to deactivate thecompressor and provide exterior air into the room interior when thedesired cooling temperature is less than the current room interiortemperature and bringing exterior air into the room interior would beadvantageous in cooling the interior area.

The foregoing description of structures and methods has been presentedfor purposes of illustration. It is not intended to be exhaustive or tolimit the invention to the precise steps and/or forms disclosed, andobviously many modifications and variations are possible in light of theabove teaching. It is intended that the scope of the invention bedefined by the claims appended hereto.

1. An window fan for cooling a building interior, comprising: a housinghaving an exterior side for positioning exteriorly of said building andan interior side for positioning interiorly of said building; saidhousing having an outside air intake though which outside air isentrained on said exterior of said building, said outside air intakepositioned lower on a surface of said housing; said housing having anoutside air output in fluid communication with said outside air intake,said outside air output positioned in said building interior; saidoutside air intake and said outside air exhaust in fluid communicationwith a first fan; said outside air intake having an outside louver, saidoutside louver having a preselected geometry which inhibits rain fromentering said duct; a first motor connected to said first fan causingrotation and entraining of said outside air from said building exteriorinto said air intake; an inside air exhaust on an exterior surface ofsaid housing positioned above said outside air intake, said inside airexhaust forcing contaminants in said outside air away from said outsideair intake; a dam disposed interiorly of said air intake, said daminhibiting contaminants from passing through said duct in said housing;a second exhaust fan which rotates to draw air from said buildinginterior and forces air outward near a base of said housing; a secondmotor connected to said second exhaust fan causing rotation andentraining of said inside air from within said building to outside saidbuilding.
 2. The window fan for cooling a building interior of claim 1,said outside air output and said inside air intake on said housing forpositioning in said building interior.
 3. The window fan for cooling abuilding interior of claim 2 further comprising actuatable louvers onsaid outside air output and said inside air intake.
 4. The window fanfor cooling a building interior of claim 3, further comprising a controlpanel for operating said window fan.
 5. The window fan for cooling abuilding interior of claim 4, said control panel including an electroniccontroller which signals opening and closing of said actuatable louvers.6. The window fan for cooling a building interior of claim 1 having afirst airflow path and a second airflow path.
 7. The window fan forcooling a building interior of claim 4, said first airflow pathseparated from said second airflow path separated by a partition.
 8. Thewindow fan for cooling a building interior of claim 7, one of said firstairflow path and said second airflow path drawing air into said buildinginterior.
 9. The window fan for cooling a building interior of claim 8,the other of said first airflow path and said second airflow pathdrawing air from said building interior.
 10. The window fan for coolinga building interior of claim 7, said partition having a sloped surfacefor draining any water from the housing.
 11. The window fan for coolinga building interior of claim 1 further comprising a well positionedadjacent said dam for collecting water and draining said water from saidhousing.
 12. A window fan system, comprising: a housing having a frameand a partition defining a first air flow path and a second airflow paththrough said housing; one of said first and second flow path drawingoutside air into a building and the other of said first and second flowpath drawing inside air out of the said building creating a circulationpath; a first blower in fluid communication with said first airflow pathand a second blower in fluid communication with said second airflowpath, said first and second blowers creating airflows; a dam disposedalong one of said first and second airflow path, said dam inhibitingwater from passing from through said housing with said outside air, saiddam having a sloped surface causing said water to gravity drain to awell; said well having drain apertures releasing said water from saidhosing interior to said exterior; a rear louver disposed over the insideair exhaust and outside air intake, said louver having a plurality offins of preselected geometry which inhibit passage of water through saidlouver; said inside air exhaust blowing water and contaminants away fromsaid outside air intake.
 13. A window fan for cooling a buildinginterior by using exterior air having preselected characteristics,comprising: a housing having an air intake and an air exhaust outputboth in said housing and on an exterior side of said building; an airoutput on an interior side of said building, said air output in fluidcommunication with said air intake through a duct in said housing; saidair exhaust in fluid communication with an exhaust intake on a buildinginterior side of said housing; a first fan disposed vertically above asecond fan within said housing; one of said first fan and said secondfan in flow communication with said air intake and said air output, theother of said first fan and said second fan in flow communication withsaid air exhaust and said exhaust intake.
 14. The window fan for coolinga building interior of claim 13, said first fan and said second fandrawing warmer air from said interior side of said building and coolerair from said exterior side of said building.
 15. The window fan forcooling a building interior of claim 14, said first fan and said secondfan removing warm air from in said building and increasing circulationfor improved cooling.
 16. The window fan for cooling a building interiorof claim 13, further comprising a partition separating a first airflowpath from a second airflow path.
 17. The window fan for cooling abuilding interior of claim 16 further comprising said first airflow pathand said second airflow path moving in opposite directions through saidhousing.
 18. The window fan for cooling a building interior of claim 13further comprising a movable louver system for positioning on a buildinginterior side of said housing.
 19. The window fan for cooling a buildinginterior of claim 18 further comprising at least one actuating motorconnected to a linkage for opening and closing louvers.
 20. A window fansystem, comprising: a housing having a control panel; a first airflowpath having a first blower drawing outside air into said system andexhausting said outside air into said system and exhausting said outsideair inside a building; a second airflow path having a second blowerdrawing inside air into said system and exhausting said inside airoutside said building; and, a room air intake in flow communication withsaid second airflow path and an outside air exhaust in flowcommunication with said first airflow path, said room air intakedisposed above said outside air exhaust.
 21. The window fan system ofclaim 20 further comprising a dam positioned generally along said secondairflow path and inhibiting water from reaching said second blower. 22.The window fan system of claim 21 further comprising a well disposed ata lower edge of said dam.
 23. The window fan system of claim 20 furthercomprising a louver system which closes said first and second airflowpaths.
 24. The window fan system of claim 23 further comprising a motorwhich actuates a linkage.
 25. The window fan system of claim 24, saidlinkage actuating a plurality of louvers in said first airflow path. 26.The window fan system of claim 25, said linkage actuating a plurality oflouvers in said second airflow path.